Rotary well bore cleaner



June 1946. K. A. WRIGHT ROTARY WELL BORE CLEANER Filed Jun e 26, 1944 2 Sheets-Sheet 1 INVENTOR. A ennefb /1. \l/m hf' /fi June 18, 1946. K. A. WRIGHT ROTARY WELL BORE CLEANER Filed June 26, 1944 2 Sheets-Sheet 2 present invention is operated through a well casing it presents smooth continuous parts which are effectively lubricated by the fluid in the well so that the device offers a minimum of friction or resistance to movement. a

Another object of the invention is to provide a device of the general character referred to having abrading members yieldingly mounted to normally project in a mannerto effectively act on a mud cake. These members may be plates or blades or they may be wires mounted to have abrading, scratching or scraping action and are designed to effectively scrape or peel the mud cake from the formation wall.

Another object of this invention is to provide a device of the general character referred to having a. semi-rigid mounting which will hold the casing away from the formation wall regardless of the inclination'of the well bore.

Another object of this invention is toprovide a construction which permits free and undamaged travel of the device through restricted openlugs, and causes expansion of the abrading members into enlarged portions of the hole so the mud is effectively removed even though the con- Another object of this invention is to provide a device of the general character referred to which does not materially impede circulation of fluids in the well or within the casing as the device is being lowered therethrough. The structure of the present invention provides units that may be spaced circumferentially so that there are clear unobstructed channels for fluid circulation.

Another object of the present invention is to provide cleaner units of the general character above referred to which can be spaced longitudinally of the operating string and also circumferentially thereof as the operator desires, giving great latitude as to arrangement.

The various objects and features of my invention will be fully understood from the following detailed description of typical preferred forms and applications of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a view illustrating the lower end portion of a well that has been drilled by the rotary method and which has a casing set therein and showing the structure of the present invention on an operating string in the well and below the lower end of the casing to operate on the mud cake on the wall of the well. Fig. 2 is an enlarged detailed transverse sectional View of the operating string taken at the point where it is provided with the structure of the present invention showing several units of the present invention spaced around the operating string and showing the units fully expanded. Fig. 3 is a view similar to Fig. 2 showing the units of the present invention collapsed or contracted within a casing as is the case while the structure is being passed through a casing. Fig. 4 is a side elevation of one of the units of the present invention showing it detached from the operating string. Fig. 5 is a view of a portion of an operating string showing a manner in which units of- 4 the present invention can be applied thereto. Fig. 6 is a transverse sectional view of a portion of an operating string showing a modified form of unit embodying the present invention applied thereto and in the expanded position, as is shown in Fig. 2. Fig. 7 is a view similar to Fig. 6 showing the structure illustrated in Fig. 6 collapsed as is shown in Fig. 3. Fig. 8 is a view similar to Fig. 4 showing a modified form of construction.

The device of the present invention, inaccordance with certain broader aspects thereof, may be incorporated in various forms and may be applied to an operating string in various manners. Atypical preferred form of the invention provides a plurality of individual units to be applied to the exterior of an operating string in a variety of arrangements. In the drawings I have shown two typical arrangements. In Figs. 1, 2 and 3 I have shown a plurality of units arranged in several rows disposed longitudinally of the operating string and circumferentially spaced around the operating string. In Fig. 5 of the drawings I have illustrated an arrangement in which the individual unitsare spaced apart longitudinally of the operating string and also circumferentially thereof to be in what may be termed a staggered arrangement.

The device of the present invention or the units provided thereby are such as to be applied to or handled on what I will term an operating string. This may be a string of pipe. or the like. such as drill pipe operated in the well specifically for the purpose of operating the cleaning units or it may be a pipe or casing intended to be left in the well as a part of the final well assembly. The operating string is essentially a string of pipe and may be either the surface or production casing or it may be the oil string which is left permanently in the well.

When the invention is used on drill pipe or tubing and the pipe is moved, either rotated or reciprocated or both, during the displacement of the cement slurry there is a proper placement of the cement against the cleaned formations. When the pipe is withdrawn the cement forms an impervious plug at the desired well depth Such placement of cement slurry opposite cleaned formation is a great improvement over present technique for installing plugs to exclude water or for directional drilling purposes- For the purpose of example it may be considered that the operating string A shown in the drawings is a string of pipe lowered into the well for the specific purpose of handling and operating the units of the present invention.

In Fig. l of the drawings I have illustrated a well bore B with a casing C set. therein, at a suitable point above the bottom, and I. have shown the operating string A extending into the well bore below the casing C to there carry the units D of the present invention so that they are operable on the mud cake E occurring on the wall of the well bore.

The units of the present invention, regardlem of how theyare arranged or disposed in the operating string and whether the string be drill pipe or a casing, may be alike or substantially alike and. therefore, I will proceed to describe the construe tion of a single unit, it being understood that such description applies equally well to the several units that may be assembled on the operating string.

Referring in particular to the form of unit fllustrated in Figs. 1 to 5 of the drawings, inclusive,

which serves as the means for mounting the unit on the exterior of the operating. string A and to carry or support the body H. The body ll is preierably a unitaryor integral memben formed of rubber, or the like, and is retained or held by the base iii. The body is capable of expansion to an expanded or full operating position, as is shown in Fig. 2, and is collapsible to a retracted or collapsed position such as is shown in Fig. 3. The blade i2 is a metal element supported on the outer or projecting part of the body to project therefrom so that it will engage the mudcake to remove it from the well bore. r

The base it? in the preferred form of constructhatin practice various details rated in the trailing portion or side of the body that will allow it to readily fold in the manner tion is a sheet metal Part preferably formed of in. the case illustrated the base is provided with projecting fianses or cars ii formed and related to grip and hold the body ii. It is preferred to locate the ears ii at the longitudinal edges or margins of the plate portion it and to shape 1 or form them so that the ears at the opposite edges of the plate portion bear inwardly toward each other and thus confine and grip the body iii. It will be apparent that the flanges may be varied widely in shape and number and that they can be readily operated into pressure engagement with the body ii to firmly and securely hold it. The body ii is preferably an integral unit formed of rubber or the like. For use in oil wells where hydrocarbons are present it is preferred to form the bodies ii of synthetic rubber of a kind or grade that is not attacked by oils.

The body ii is an elongate member overlying the base It and may, in practice, correspond genorally in length and width to the base it. The

body is formed or designed so that it is normally maintained in the expanded position shown in Fig. 2, by reason of the shape or inherent form and characteristics of the body itself, and yet is subject to being deflected or collapsed from the extended position to a collapsed position such as is shown in Fig. 3.

In the preferred form the body is generally triangular in cross sectional configuration in which case it has a base Ill that bears on or against the plate portion ii of the base l0, sides l8 and H which extend outwardly irom the margins of the base I0 and converge to form an apex portion it. To facilitate the desired operation of the body the side to which is the leading side of the structure is operated or rotated in the direction indicated by the arrows in the drawings may be a continuous or plain flat wall such as is best illustrated in Fig. 2 of the drawings. With a plain or flat formation of the leading side oi the shown in Fig. 3. 1

In accordance with the preferred form of the invention means is provided to facilitate the collapse of the body in addition to the folding above described. In the form of the invention shown in Figs. 2 and 3 this additional means isprovided by recesses 25 in the base 18 of the body. When the body is collapsed the recess 25 is fiattened so that its wall conforms to the plate portion of the base and is not apparent, a will be seen in Fig. 3 of the drawings.

In Figs. 6 and 7 oi the drawings I have illustrated another manner whereby collapse oi the body can be facilitated. In this case longitudinal openings or cavities 25 are provided in. the body and are such as to flatten out so that their opposite walk bear on one another as is shown in Fig. '7-when the body is moved to the collapsed position.

In the preferred form of the invention the body ii has cuts 38 formed transversely of its axis at points spaced along its length and extend the tool operates. The blade has an inner mounting portion 38 which is embedded in the body to be retained thereby. This portion of the blade may have openings 87 occupied by the material of the body so that the bodysecurely retains the blade.

In accordance with the preferred form or the invention the blade projects from the apex portion is of the body so that it is substantially re.-

body the trailing side i l is preferably relieved as by a recess is so that it can be readily folded over or collapsed to aposition such as is shown in Fig. 3. In the particular case illustrated I have dial 0! the operating string A when the body is fully expanded, as is shown in Fig. 2, and barely clears the inner wall 60 of the well casing C when the body is collapsed to facilitate passage through thewell casing. In this way the blade is made fully active against the mud cake when the body is expanded and it i prevented from being iniured or worn by the casing as it is being passed therethrough.

The blade 12 may be divided. along its length so that it is in sections corresponding generally to the sections into which the body is divided by the cuts 30. In fact, as shown in Fig. 4 of the drawings, the blade may be divided within each section of the body'so that instead or being one continuous blade as it may be in some cases, it is in the form of a plurality of individual blade parts each capable of independent or individual movement. flexibility that may be highly desired in some cases. In the form of the invention shown in Fig. 8 the blades instead of being fiat are in the term of wires 12. The wires are shown held or anchored to a tie l2 embedded in thebody II;

The blade I2 is preferably formed of steel or like metal and its end or the ends 45 of its several sections are preferably rounded off as shown in Fig. 4 to-minimlze any danger or it being caught on obstructions that may occur in the well casing.

In using units provided bythe present invention they may be arranged in several row lengthcan be income This construction gives the device wise of the operating string A which rows are spaced circumferentially of the operating string as is shown in Figs. 1, 2 and 3 of the drawings, or they may be arranged in any manner that the operator desires to obtain the best results. In Fig. 5 the staggered arrangement is typical of an alternative arrangement that can be used.

In accordance with the broader aspects of the present invention the unit constructed as above described can be applied to the operating string in any suitable manner. It is preferred to apply the units to the outer surface or wall l6 of the operating string and, in practice, this can be done most advantageously by welding Wapplied along the edges of the base in Joining the edge portions of the base In with the operating string A. Throughout the drawing I have shown this welded form of mounting but do not wish to be understood as limiting the invention to, this or any other specific form or mounting that may be employed.

The units of the present invention applied to the operating string A can be readily passed through the well casing C to a point below the lower end 01 the well casing. The bodies of the units collapse as they are passed through the well casing and are in the position shown in Fig. 3 while they are within the casing. It is to be noted that the leading sides l6 of the units have portion racing or bearing outwardly against the casing wall 40 forming bearings that are smooth and which allow free movement of the units through the casing. With fluid present in the well, as it normally is, and the bodies ll being formed of rubber or the like, the faces or sides It which bear on the wall of the casing do so with a minimum of friction and without wearing or destroying the units.

During the passage or the unit through the casing its operating blade or blades are deflected from active position so that they do not catch Fig. 2, operate the blades outwardly into engagernent with the mud cake and as the mud cake is cut away the blades continue to expand until they have reached their maximum or fully expanded position, as shown in Fig. 2.

Because of the construction above described if an obstruction is encountered at any particular point the entire structure is not rendered inoperative. By rotating the operating string and advancing it longitudinally in the well bore either upwardly or downwardly the bore can be effectively cleaned of the mud cake E. The operating string can be rotated, or reciprocated, or both rotated and reciprocated. It is preferred in practice, of course, to employ the structure of the present invention in carrying out the method taught in my above mentioned patent. However, the nature of the present invention is such that it is not necessarily limited to any particular method of operation. It can be used to advantage on drill pipe intended to be removed from the well or on casing which is to be left or cemented in the well.

Having described only typical preferred forms and applications of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but w sh to reserve to myseli 8 any variations or modifications that may appear to those skilled in the art-and fall within the scope ,of the following claims. 1

Having described my invention, I claim:

1. A device of the character described for use on an elongate operating member and for passage through a casing, or the like, including, a body of rubber for attachment to the operating member, and a straight elongate blade carried by and projecting substantially radially outward body of rubber for attachment to the operating member, and a straight elongate blade carried by the body to extend parallel with said member and projecting outwardly from the body, said body and blade normally projecting a substantial distance from the operating member to which the body is applied, the body being so arranged as to be subject to being circumferentially folded inward by a surrounding medium when in a well to position the :blade inwardly of its normal position, the body being an elongate member divided transversely into a plurality of sections freeto fold individually, the blade being sectional and having a section carried by each section of the body.

3. A device of the character described for use on an elongate operating member and for passage through a casing, or the like, including, a body of rubber for attachment to the operating member, and a straight elongate blade carried by and projecting substantially radially outward from the body to extend parallel with the operating member, said body and blade normally projecting a substantial distance from the operating member to which the body is applied, the body being so arranged as to be subject to being circumferentially folded inward by a surrounding medium when in a well to position the blade inwardly of its normal position, the blade being divided transversely into a plurality of independently movable sections.

4. A device of the character described for use on an elongate operating member and for passage through a casing, or the like, including, an

' elongate body of rubber for attachment to the operating member to extend parallel therewith,

and a straight, elongate, rigid working element carried by the body to extend parallel therewith and projecting outward from the body, the body and element normally projecting a substantial distance from the operating member, the body being so arranged as to be subject to being circumferentially folded inward by a surrounding medium when in a well to position the working element inwardly of its normal position, there being an opening in the body lengthwise thereof to facilitate folding thereof.

5. A device of the character described for use on an operating member and for passage through a casing, or the like, including, an elongate body of rubber having a recessed base portion to be supported on the operating member, and side walls that project from the base portion and converge to an apex portion, and a working ele- Q ment carried by and projecting outward from the apex portion of the body, one of the side walls being recessed so the body will fold circumferentially inward to position the working element inwardly of its normal position.

6. A device of the character described for use on an operating member and for pasmge through a. casing, or the like, including, an elongate body of rubber having a longitudinally recessed base portion to be supported on the operating member, and side walls that project from the base portion and converge to an apex portion, and a working element carried by and projecting outward from the apex portion of the body, one side of the body having a longitudinal recess therein arranged to facilitate folding of the outer portion of the body circumferentially inward for passage through a casing.

7. A device of the character described for use on an operating member and for passage through a casing, or the like, including, an elongate body of rubber having a base portion to be supported on the operating member, and side. walls that project from' the base portion and converge to an apex portion, and a working element carried by and projecting outwardly from the apex portion of the body, one side of the body being smooth and continuous to slide-on the casing when the body is folded circumferentially for passage through a casing, the other side of the body being longitudinally recessed to facilitate such folding of the body.

8. In combination, an operating string and a plurality of elongate units arranged longitudinally of the string and spaced apart circumferentially thereof, each unit including a body of rubber longitudinally recessed so it is free to fold circumferentially of the string to facilitate passage of the string through a casing and a. work element carried by the foldable portion of the body to normally project radially outward from the string and to project substantially circumierentially of the string when the body is folded.

KENNETH A. WRIGHT. 

